The present invention concerns a nozzle valve for spraying of machine parts, especially for oil cooling of pistons in internal combustion engines, from a housing, a nozzle, a valve body such as a ball, and at least one spring means such as a coil spring. The housing includes an inlet for the oil which is positioned behind the valve body. The valve body is loaded by the spring means directly supported thereon counter to the flow-through direction of the oil in the direction toward a valve seat at the inlet. The spring means lies against a support on the side facing away from the valve body.
Such a nozzle valve, i.e., a structural unit consisting of a spring-loaded flow-through valve with a following nozzle, is known from EP 0 346 264 A2, which is considered as defining the type. This includes sheet-metal elements assembled in sandwich fashion, between which the nozzle is formed. In this state of the art, the valve is articulated orthogonally to the nozzle and is produced by shaping one of the upper sheet-metal elements.
A disadvantage of this known nozzle valve is the fact that it has a relatively complicated design. Forming the nozzle by shaping the sheet-metal elements has also proven to be relatively problematic. The spray stream can be adjusted only with difficulty. Moreover, it must be remembered that the nozzle valve consists of relatively many parts, increasing production costs. In addition, the sandwich-like mode of construction is accompanied by limitations with respect to the point of installation of the nozzle valve. Thus, due to its length, such a valve can only be installed laterally on the crankcase or cylinder head of the internal combustion engine. Installation in a connecting rod, a connecting-rod eye, or a rod bearing is out of the question.
The object of the present invention is therefore to create a nozzle valve of the above-mentioned type in which the cited disadvantages are eliminated. In particular, it should be formed from only very few parts and be simple to produce.
This goal is attained by providing both end walls of the housing with a collar directed radially inwardly. The valve seat is formed by an inner surface of the first collar and a separately produced support resting on an inner surface of a second collar, with this support being formed as one piece with the nozzle.
Through this improvement according to the present invention, a nozzle valve is created which is very simple to manufacture and which includes only a few parts. Its housing should preferably be formed of a thin-walled material, such as deep-drawn sheet metal. However, it can also be manufactured via a machining process. The housing can likewise be manufactured in principle from a material for light construction such as a polymeric material. It is further conceivable to forgo the housing completely as a structural element. The structural parts including the nozzle with valve body and the spring means are then positioned directly in a cavity of the internal combustion engine. This cavity or the cavity for the nozzle valve with housing can range, for example, within a connecting rod, a connecting-rod eye, a wall of a cylinder head, or a wall of a crankcase of the internal combustion engine. It is also conceivable to position this cavity in the cap of a rod bearing, which cap is bolted in place as a rule.
As a result of the proposed one-piece design of the nozzle with the support for the spring, with simultaneous direct support of the other side of the spring against the valve body, the nozzle valve exhibits only a small number of structural parts. It is simultaneously very compact. A ball is preferably employed as the valve body. However, it is also conceivable to form the valve as a disk valve or the like. The coil spring can also be formed as a spiral or plate spring.
A nozzle valve having an especially short design if, following a further refinement of the present invention, the support with nozzle extends completely within the housing. This precise design is suitable for applications of the nozzle valve in cramped areas.
The spring means is adapted such that the valve body keeps the nozzle valve closed with no or only slight oil pressure. In this way, undesired cooling of the corresponding piston is avoided at a lower rpm range of the internal combustion engine and therefore at a lower output of the oil pump. As is known, cooling of the piston is desired only at higher rpm and load conditions of the internal combustion engine. Thus, at lower rpm of the internal combustion engine, the full oil pressure in the lubricating-oil circuit is available for lubrication of the known bearing points.
It can also be advantageous to have the support with nozzle protrude tubularly beyond the second collar. In this way, the oil can be sprayed while being particularly directed toward the piston to be cooled. The nozzle can be constructed better with respect to its characteristic performance curve, i.e., substantially loss-free conversion of pressure energy into kinetic energy.
According to a further subclaim, the support with nozzle is provided with an annular projection extending along the inner surface of the housing. This annular projection, on the one hand, stabilizes the entire nozzle valve. On the other hand, it is possible through this projection to form a stop for the valve body in the opening direction, against which the valve body permanently rests beginning at a certain pressure of the oil at the inlet. Passage of the oil occurs via defined cross-sections such as segment-like openings or longitudinal recesses in the annular projection or, upon xe2x80x9cfree flightxe2x80x9d of the valve body, only between the latter""s outer surface and the housing.
It is particularly favorable with respect to manufacturing engineering if the support with nozzle is manufactured from a material for light construction such as plastic. Both structural parts should preferably be produced as one piece. Simple injection molding is suitable here.
According to a further refinement of the present invention, the first collar is transformed at its inner edge into an axial ring, such that a simply formed valve seat is created for the valve body in its closed position. One can thus forgo the need for a subsequently applied valve seat ring or the like.
Finally, further embodiments of the present invention concern the formation of the nozzle. Thus, a mouth of the nozzle positioned on the side of the inlet can be provided with a conical or rounded-off or even beveled edge. The person of skill in this field will be able to determine which nozzle design is the most appropriate for a particular application.
One use of the nozzle valve according to the present invention relates particularly to the spraying of pistons in internal combustion engines, but the range of protection of this invention is not limited only to this application. Many other applications are envisioned, such as in machine construction or elsewhere in which the proposed simply constructed nozzle valve can be used for spraying with a liquid medium.